Develop Reference

Get path for data storage

I need to create file in storage card from my Android program. I know I can create this file only in particular location like \Card\Android\data\my.application.package\. How to get this directory exact location? Code below brings path /data/my.application.package/Log and mkdirs() does not creates directories.
String path = "Log";
File root = new File(Environment.getDataDirectory().getAbsolutePath(),
"my.application.package" + File.separator + path);
boolean dirExists = true;
if (!root.exists()) {
dirExists = root.mkdirs();
}
How to get the same application path on internal storage?

You should use getFilesDir() for getting app specific internal File path and getExternalFilesDir() for getting app specific external File path.
Note that on Android 4.3 (API level 18) or lower, your app need to request storage-related permissions to access app-specific directories within external storage.
For more information see https://developer.android.com/training/data-storage/app-specific

getting data from internal storage

I'd like to read all files located in internal storage and filter them to find those *.mp3 ones. With external storage I could just use:
final String MEDIA_PATH = Environment.getExternalStorageDirectory().getPath();
to get the path, but I cannot find the way to do it for internal memory (for instance to get to Music folder of the phone). Is there a way to do it?

Are you aware of getFilesDir() method?
http://developer.android.com/training/basics/data-storage/files.html

You can use Context.getFilesDir() method to get the path to the internal storage.
Like : File file = new File(getFilesDir() + "/" + name);

How do I get the external storage's path?

I'm trying to write a file to my phone.
I used Environment.getDataDirectory() to know the internal storage's path and Environment.getExternamStorageDirectory() to know the external storage's path.
But when I use Environment.getExternalStorageDirectory() as path, the file is created in internal storage. And when I use Environment.GetDataStorage() as the path, the file is not created. (I am not sure, but I can't find it in the explorer app, at least.)
I think my phone's internal storage is perceived as external storage.(In my case, it has 32 GB amount of storage)
I want to know removable storage(e.g. micro SD card) path. What should I do?

From the official documentation for getExternalStorageDirectory()
Don't be confused by the word "external" here. This directory
can better be thought as media/shared storage. It is a filesystem that
can hold a relatively large amount of data and that is shared across
all applications (does not enforce permissions). Traditionally this is
an SD card, but it may also be implemented as built-in storage in a
device that is distinct from the protected internal storage and can be
mounted as a filesystem on a computer.
So, it can be different from built-in storage in a device.
For your case, you could use getExternalStoragePublicDirectory(java.lang.String)
This is where the user will typically place and manage their own
files
The path here should be one of DIRECTORY_MUSIC, DIRECTORY_PODCASTS,
DIRECTORY_RINGTONES, DIRECTORY_ALARMS, DIRECTORY_NOTIFICATIONS,
DIRECTORY_PICTURES, DIRECTORY_MOVIES, DIRECTORY_DOWNLOADS, or
DIRECTORY_DCIM. May not be null.
Or if you want your data to be deleted whenever the user uninstalls your app, you could use getExternalFilesDir().
As these files are internal to the applications, and not typically visible to the user as media.
Also there are some differences between getFilesDir() and getExternalFilesDir()
External files are not always available: they will disappear if the user mounts the external storage on a computer or removes it. See the APIs on environment for information in the storage state.
There is no security enforced with these files. For example, any application holding WRITE_EXTERNAL_STORAGE can write to these files.

Try this...
static String storagestate = Environment.getExternalStorageState();
private static FileOutputStream outStream;
private static File imageFilepath;
public static String saveImage(Bitmap bitmap) {
File folder = null;
// Check for SD card
if (storagestate.equals(Environment.MEDIA_MOUNTED)) {
folder = new File(Environment.getExternalStorageDirectory(),
"*YourStorageNameInDevice");
if (!folder.exists()) {
folder.mkdir();
}
outStream = null;
String timestamp = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS")
.format(new Date());
// Getting filepath
imageFilepath = new File(folder.getPath() + File.separator
+ timestamp + ".PNG");
try {
outStream = new FileOutputStream(imageFilepath);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, outStream);
outStream.flush();
outStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
return imageFilepath.getAbsolutePath();
}
}

using external storage?

I want to use the sdcard as a storage support of my application's data, the problem I encountered the path varies depending on the manufacturer, I do not have the same configuration for all tablets. I used the code below.
File root = Environment.getExternalStorageDirectory();
String Path = root.getAbsolutePath().toString();
File mFile = new File(Path+ "/fileName");
if(mFile.exists()){
mFile.delete();
}
With some tablets the job is done and the file is deleted with other no. So can you tell me how to get the external storage for all tablets.

File has a constructor that takes two parameters. A file and a String.
File root = Environment.getExternalStorageDirectory();
File mFile = new File(root, "fileName");
if(mFile.exists()){
mFile.delete();
}

save image to sdcard android Directory problem

Im trying to save data to sdCard first i tried to saave it privately within app directory on externalStorage using getExternalFilesDir but gives me nullPointerException so i tried the other way given below it worked but when i want to store files into a custom directory that i want to named myself it give me error:
FileOutputStream os;
dirName = "/mydirectory/";
try {
if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED)){
File sdCard = Environment.getExternalStorageDirectory();
File dir = new File (sdCard.getAbsolutePath() + dirName);
dir.mkdirs();
//File file = new File(this.getExternalFilesDir(null), this.dirName+fileName); //this function give null pointer exception so im using other one
File file = new File(dir, dirName+fileName);
os = new FileOutputStream(file);
}else{
os = context.openFileOutput(fileName, MODE_PRIVATE);
}
resizedBitmap.compress(CompressFormat.PNG, 100, os);
os.flush();
os.close();
}catch(Exception e){
}
ErrorLog:
java.io.FileNotFoundException: /mnt/sdcard/mvc/mvc/myfile2.png (No such file or directory)

Your directory "/mnt/sdcard/mvc/mvc" may not exist. What about changing your path to store the image in the Environment.getExternalStorageDirectory() path and then working from there?
Also, as Robert pointed out, make sure you have write permission to external storage in your manifest.
Edit - to create directories:
String root = Environment.getExternalStorageDirectory().toString();
new File(root + "/mvc/mvc").mkdirs();
Then you can save a file to root + "/mvc/mvc/foo.png".

Have you requested permission to write onto SD card? Add the following string to you app manifest:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

You should check if you have added the required permission android.permission-group.STORAGE to your app. Without that permission you won't be able to access anything on the SD-Card.
BTW: On the Android system I know the SD-card is mounted on /sdcard not /mnt/sdcard

I found this book to be very helpful: "Pro Android Media: Developing Graphics, Music, Video, and Rich Media Apps for Smartphones and Tablets". I noticed a part that allows saving images and stuff to the SD card.